"We are very sorry for the inconvenience and we appreciate everyone’s patience."

Facebook – and partner apps Instagram and WhatsApp – went offline for many users at around 4pm yesterday.

It sparked online panic as social media users found themselves unable to make or view new posts.

In a tweet sent during the outage, Facebook wrote: "We're aware that some people are currently having trouble accessing the Facebook family of apps. We're working to resolve the issue as soon as possible."

A tweet (since deleted) by Derek Gannon, who reports on terrorism, soon went viral with the claim that Facebook data seemed to suggest the site was being targeted by a DDoS attack from a "nation state".

A DDoS, or distributed denial of service, is when hackers flood a website's servers with information, overloading them and taking the website down.